1# SPDX-License-Identifier: GPL-2.0 2# 3# Building vDSO images for x86. 4# 5 6# files to link into the vdso 7vobjs-y := vdso-note.o um_vdso.o 8 9# files to link into kernel 10obj-y += vdso.o vma.o 11 12vobjs := $(foreach F,$(vobjs-y),$(obj)/$F) 13 14$(obj)/vdso.o: $(obj)/vdso.so 15 16targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y) 17 18CPPFLAGS_vdso.lds += -P -C 19 20VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \ 21 -Wl,-z,max-page-size=4096 22 23$(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so 24 25$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE 26 $(call if_changed,vdso) 27 28$(obj)/%.so: OBJCOPYFLAGS := -S 29$(obj)/%.so: $(obj)/%.so.dbg FORCE 30 $(call if_changed,objcopy) 31 32# 33# Don't omit frame pointers for ease of userspace debugging, but do 34# optimize sibling calls. 35# 36CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ 37 $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \ 38 -fno-omit-frame-pointer -foptimize-sibling-calls 39 40$(vobjs): KBUILD_CFLAGS += $(CFL) 41 42# 43# vDSO code runs in userspace and -pg doesn't help with profiling anyway. 44# 45CFLAGS_REMOVE_vdso-note.o = -pg -fprofile-arcs -ftest-coverage 46CFLAGS_REMOVE_um_vdso.o = -pg -fprofile-arcs -ftest-coverage 47 48# 49# The DSO images are built using a special linker script. 50# 51quiet_cmd_vdso = VDSO $@ 52 cmd_vdso = $(CC) -nostdlib -o $@ \ 53 $(CC_FLAGS_LTO) $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \ 54 -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) 55 56VDSO_LDFLAGS = -fPIC -shared -Wl,--hash-style=sysv -z noexecstack -Wl,--no-undefined 57